And another thing to try:
Update your audio drivers (strange that this would be necessary as there hadn't been any changes for me; but it usually is a good idea to have the latest drivers anyway).
Note: We did have a PC whose audio stopped working and a BIOS update solved it. This definitely wasn't the root of the problem for that computer because it was working like normal before and there were no apparent changes (and the user didn't have administrative access). I'd recommend this as a last step. I've never had a problem with a BIOS update but prefer to do it only if there is a useful fix (and of course better to back up before).
Here's another solution that someone posted:
I had the realtek error when using the installer, so I did these step and It Worked
note: make sure before doing these steps that you have driver enforcement disabled
< I don't know if this is necessary but that's what the poster suggested. - hr0201>
1.Go Open up device manager
2. Go under sound,video, and game controllers
3. Find Realtek High Definition Audio
4. Right click and hit update driver
<< I would think just updating the driver would probably work, but if not (for instance if it's up-to-date) then you could try the following steps as well. - hr0201>>
5. Browse my computer for driver software
6. Let me pick from a list of available drivers on my computer
7. Click Have Disk and hit browse
8. Click on the Realtek HD Audio mod folder and look for win64
9. Click on the HDXRT4 and click ok,
10. Click Next and Yes
After it is done, restart the PC
You should be good then and also make sure before doing these steps that you have driver enforcement disabled.
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